The present invention relates to an apparatus for and a method of pre-exposing photographic film with images.
It is known to provide photographic film which has been partly exposed in regions of each film frame with an image which is retained as a latent image. The user who loads the film then exposes the film in the normal manner in a specially adapted camera. The camera includes some masking arrangement to mask out the area of the film which bears the latent images, so that these are not double-exposed. When the film has been exposed by the user, it is processed and developed in the normal way, the finished pictures bearing both the pre-exposed images provided by the manufacturer (hereinafter referred to as xe2x80x9cpre-exposed imagesxe2x80x9d), and the user-exposed images thereon. For example, it can be arranged that the film is pre-exposed with a decorative strip which carries a message such as xe2x80x9chappy birthdayxe2x80x9d or xe2x80x9cwish you were herexe2x80x9d, the camera including a strip-like mask in the exposure window to prevent double-exposure of the pre-exposed film region.
Various pre-exposure techniques are known. For example, it is known to place the unexposed film in contact with a length of master film carrying a sequence of images thereon, and to move both past a light source, whereby the images are transformed to the unexposed film. This method is not only time-consuming, but is inflexible in terms of the images which can be produced.
It has also previously been proposed by the applicant in U.S. Pat. Ser. No. 09/092,607 to utilize a technique whereby the images are stored digitally and generated by a cathode ray tube beam which is scanned sequentially over each film frame. In a further development, the image is generated on a computer monitor. These techniques allow a wide variety of different selected images to be readily stored in a computer memory or disc, retrieved and exposed onto the film. In this method, the film comprises a bulk roll of film which must, once pre-exposed, still be further handled by cutting into appropriate lengths and placed into the film cassette, which is both time-consuming and thereby expensive.
The present invention seeks to provide an apparatus and a method allowing simultaneous pre-exposure and film loading.
In recent years cameras known variously as disposable or single-use cameras, or referred to by some as lens-fitted photographic film packages, have become increasingly popular. These are cameras of simple construction and low cost which are usually pre-loaded with film by the manufacturer. It is usually arranged that the film is unwound from the standard film cassette or patrone, and as pictures are sequentially taken the film is wound back into the cassette. Once the user finishes the film, the user returns the entire camera to the photolab for developing of the film. The manufacturer may then either discard the camera in its entirety, or subject to appropriate checks that the camera is still functional, re-load the camera. Alternatively the manufacturer may re-use specific components of the camera.
One consideration with such a camera is the ease of loading of the film, particularly given the requirement that the film must be pre-wound out of the film cassette before use. In view of the low cost of the camera itself manufacture and assembly costs are important, and this includes the cost of loading the film into the camera at the factory. It is highly desirable to utilize a method which is simple and cheap and yet reliable.
As the awareness of problems of environmental contamination increases, as well as for economic reasons, consumers are less willing to tolerate disposable products. It has previously been proposed by the applicant to provide a very simple and cheap camera of generally similar construction to a disposable camera and yet which includes adaptations allowing it to be re-used at least several times by a user.
The present invention also seeks to provide the pre-exposed film in the form of a film assembly which can be either supplied in a new camera or packaged and sold to a user who can then re-load their camera.
According to a first aspect of the invention there is provided a method of pre-exposing photographic film with latent images comprising the steps of: (a) providing a film container having a housing defining a film slot therein and a film-winding tool opening; (b) providing a roll of unexposed film; (c) securing a leading end of the film to a film-winding tool arranged on the opposite side of an exposure opening from said roll of unexposed film and enclosing the film leading end and winding tool end in the container with the tool extending from the film-winding tool opening; (d) enclosing the film container and roll of film in a light-tight enclosure; (e) sequentially exposing the film to a series of images directed onto the film, and advancing the film by rotating the film-winding tool between each exposure; (f) withdrawing the film-winding tool from the container and closing said opening therein; and (g) opening the enclosure and removing the film container having the pre-exposed film loaded therein.
In one embodiment, the roll of unexposed film is provided wound in a further film container, which is a conventional film patrone.
The combination of conventional film patrone and additional film container with the majority of the pre-exposed film wound therein but connected to the film patrone constitutes a film assembly which can be loaded into a new camera for sale to a user, or may be packaged for sale to a user allowing the user to re-load their camera, as discussed further below.
As an alternative to providing the unexposed film in a film patrone, the roll of unexposed film can be a bulk roll of film, the method further involving prior to step (g), cutting the wound pre-exposed film from the bulk roll, and after step (g), securing the cut end to a further film container. The further film container is then preferably a conventional film patrone having a central spool, the cut end being secured to the spool.
In a preferred embodiment the film container has a housing having an open end closed by an end cover which defines therein an opening closed by a resiliently biased shutter plate, at step (f) the shutter plate closing the said opening on removal of the film-winding tool. At step (c) the film-winding tool end is inserted through the opening of the end cover with the end cover detached from the housing and the shutter open, and thereafter the film end is secured to the film-winding tool, followed by securing the housing to the end cover.
The method may involve the step of cutting a film alignment notch into an edge of the film.
The advance of the film may be detected by sensing means adapted to stop the film advance and output a signal communicated to said film exposure means after the advance of the film through a distance corresponding to one film frame.
In a further aspect the invention resides in an apparatus for pre-exposing film with latent images comprising: means for enclosing a roll of unexposed film; means for enclosing a film container adapted to receive pre-exposed film; a film-winding tool extending into said means for enclosing the film container; and image generating means for generating an image to be exposed onto the film. The film-winding tool is retractable whereby it can be at least partly withdrawn from the means for enclosing the film container. The means for enclosing the roll of unexposed film, and the means for enclosing the film container comprise a light-tight housing defining an aperture through which said film-winding tool extends.
The sensing means is preferably arranged to detect the passage of the film, the sensing means being operatively connected to control means, which control means are operatively connected to the film-winding tool. The control means is a computer or other processing means programmed to control the film-winding tool and the image generating means.
The sensing means may comprise a sprocket wheel for contacting the film, connected to a sensing wheel having a slot cut therein and arranged to rotate by one revolution for every single frame which is advanced. A rocker is provided adjacent the sensing wheel, a first arm of the rocker abutting the periphery of the sensing wheel, and a second arm engaging a relay switch, whereby a stop signal is generated when the first arm engages in the slot.
The sensor may instead comprise an infra-red sensor adapted to detect the passage of film sprocket holes.
The apparatus includes a film cutting punch to sever the pre-exposed film from the remaining exposed film, and a notch-cutting punch to cut an alignment notice in the periphery of the film.
The invention may also reside in an apparatus as described above in combination with a first film container comprising a housing and an end cover defining an aperture therein which is closed by a movable shutter plate, and further in combination with a conventional film patrone containing a roll of unexposed film.
Alternatively, the invention may reside in an apparatus described above in combination with a bulk roll of unexposed film.
In a further aspect the invention resides in a method of pre-exposing photographic film with latent images comprising the steps of: (a) providing a film container having a housing defining a film slot therein; (b) providing a roll of unexposed film; (c) securing a leading end of the film to a film-winding tool arranged on the opposite side of an exposure opening from said roll of unexposed film; (d) enclosing the film-winding too end having the leading end of film attached thereto and the roll of film in a dark environment; (e) sequentially exposing the film to a series of images directed onto the film, and advancing the film by rotating the film-winding tool between each exposure; (f) removing the wound coil of film bearing latent images thereon from the film-winding tool and enclosing this in the film container.
The film container here comprises a housing formed of two halves which co-operate to form a light-tight container having a film exit slot, wherein at step (f) the coil is placed between the halves which are secured together to enclose the coil of film therebetween with the film extending through the film exit slot.
In a still further aspect the invention resides in a method of pre-exposing photographic film with latent images comprising the steps of: (a) providing a film container having a housing defining a film slot therein and which is open at one end, and defining a film-winding tool opening; (b) providing a roll of unexposed film; (c) securing a leading end of the film to a film-winding tool arranged on the opposite side of an exposure opening from said roll of unexposed film and enclosing the film leading end and winding tool end in the housing with the tool extending from the open end; (d) enclosing the housing and roll of film in a dark environment; (e) sequentially exposing the film to a series of images directed onto the film, and advancing the film by rotating the film-winding tool between each exposure; (f) withdrawing the film-winding tool from the housing and closing the said open end with an end cap.